Hi Ashish,
On Fri, 2011-06-10 at 05:38 -0400, Ashish Jangam wrote:
> Hi Guenter,
>
> ilog2() function return int value which is causing 18% - 50% difference in the actual temperature value therefore the fixed point approx is replaced by lookup table which is computed by a formula.
>
The headline is quite misleading, since you don't submit a patch to
change ilog2() to a lookup table; instead, this is the complete driver.
One would expect to see the driver description here.
> Signed-off-by: Ashish Jangam <ashish.jangam@xxxxxxxxxxxxxxx>
> Signed-off-by: David Dajun Chen <dchen@xxxxxxxxxxx>
If David wrote the driver and you are in the internal signoff path,
sequence of signoffs should be David first, then you.
> --
... and the version change log should be here.
> diff --git a/Documentation/hwmon/da9052 b/Documentation/hwmon/da9052
> new file mode 100755
> index 0000000..0b7930f
> --- /dev/null
> +++ b/Documentation/hwmon/da9052
> @@ -0,0 +1,58 @@
> +Kernel driver da9052-hwmon
> +==========================
> +
> +Supported chips:
> + * Dialog Semiconductors DA9052 PMICs
> + Prefix: 'da9052'
> + Datasheet: Kindly visit www.dialog-semiconductor.com and request for the
> + official datasheet.
> +
> +Authors: David Dajun Chen <dchen@xxxxxxxxxxx>
s/Authors/Author/
(or list all the authors if there is more than one)
> +
> +Description
> +-----------
> +
> +The DA9052 provides an Analogue to Digital Converter (ADC) with 10 bits
> +resolution and track and hold circuitry combined with an analogue input
> +multiplexer. The analogue input multiplexer will allow conversion of up to 10
> +different inputs. The track and hold circuit ensures stable input voltages at
> +the input of the ADC during the conversion.
> +
> +The ADC is used to measure the following inputs:
> +Channel 0: VDDOUT - measurement of the system voltage
> +Channel 1: ICH - internal battery charger current measurement
> +Channel 2: TBAT - output from the battery NTC
> +Channel 3: VBAT - measurement of the battery voltage
> +Channel 4: ADC_IN4 - high impedance input (0 - 2.5V)
> +Channel 5: ADC_IN5 - high impedance input (0 - 2.5V)
> +Channel 6: ADC_IN6 - high impedance input (0 - 2.5V)
> +Channel 7: XY - TSI interface to measure the X and Y voltage of the touch
> +screen resistive potentiometers
> +Channel 8: Internal Tjunc. - sense (internal temp. sensor)
> +Channel 9: VBBAT - measurement of the backup battery voltage
> +
> +By using sysfs attributes we can measure the system voltage VDDOUT, the battery
> +charging current ICH, battery temperature TBAT, battery junction temperature
> +TJUNC, battery voltage VBAT and the back up battery voltage VBBAT.
> +
> +Voltage Monitoring
> +------------------
> +
> +Voltages are sampled by a 10 bit ADC. Voltages in millivolts are 1.465
> +times the ADC value.
> +
> +Temperature Monitoring
> +----------------------
> +
> +Temperatures are sampled by a 10 bit ADC. Junction and battery temperatures
> +are monitored by the ADC channels.
> +
> +The junction temperature is calculated:
> + Degrees celsius = 1.708 * (TJUNC_RES - T_OFFSET) - 108.8
> +The junction temperature attribute is supported by the driver.
> +
> +The battery temperature is calculated:
> + Degree Celcius = 1 / (t1 + 1/298)- 273
> +where t1 = (1/B)* ln(( ADCval * 2.5)/(R25*ITBAT*255))
> +Default values of R25, B, ITBAT are 10e3, 3380 and 50e-6 respectively.
> +
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 3236a45..da5ff6d 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -303,6 +303,16 @@ config SENSORS_DS1621
> This driver can also be built as a module. If so, the module
> will be called ds1621.
>
> +config SENSORS_DA9052_ADC
> + tristate "Dialog DA9052 HWMON"
> + depends on PMIC_DA9052
> + help
> + Say y here to support the ADC found on
> + Dialog Semiconductor DA9052 PMIC.
> +
> + This driver can also be built as module. If so, the module
> + will be called da9052-hwmon.
> +
> config SENSORS_I5K_AMB
> tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
> depends on PCI && EXPERIMENTAL
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index f7c0c28..88b81ca 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -42,6 +42,7 @@ obj-$(CONFIG_SENSORS_ASC7621) += asc7621.o
> obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
> obj-$(CONFIG_SENSORS_CORETEMP)+= coretemp.o
> obj-$(CONFIG_SENSORS_PKGTEMP)+= pkgtemp.o
> +obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
> obj-$(CONFIG_SENSORS_DME1737)+= dme1737.o
> obj-$(CONFIG_SENSORS_DS620) += ds620.o
> obj-$(CONFIG_SENSORS_DS1621) += ds1621.o
> diff --git a/drivers/hwmon/da9052-hwmon.c b/drivers/hwmon/da9052-hwmon.c
> new file mode 100755
> index 0000000..0e54508
> --- /dev/null
> +++ b/drivers/hwmon/da9052-hwmon.c
> @@ -0,0 +1,376 @@
> +/*
> + * HWMON Driver for Dialog DA9052
> + *
> + * Copyright(c) 2011 Dialog Semiconductor Ltd.
> + *
> + * Author: David Dajun Chen <dchen@xxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/da9052/da9052.h>
> +#include <linux/mfd/da9052/reg.h>
> +
> +struct da9052_hwmon {
> + struct da9052 *da9052;
> + struct device *class_device;
> + struct mutex hwmon_lock;
> +};
> +static const char * const input_names[] = {
> + [DA9052_ADC_VDDOUT] = "VDDOUT",
> + [DA9052_ADC_ICH] = "CHARGING CURRENT",
> + [DA9052_ADC_TBAT] = "BATTERY TEMP",
> + [DA9052_ADC_VBAT] = "BATTERY VOLTAGE",
> + [DA9052_ADC_IN4] = "ADC IN4",
> + [DA9052_ADC_IN5] = "ADC IN5",
> + [DA9052_ADC_IN6] = "ADC IN6",
> + [DA9052_ADC_TJUNC] = "BATTERY JUNCTION TEMP",
> + [DA9052_ADC_VBBAT] = "BACK-UP BATTERY VOLTAGE",
> +};
> +
> +/*
> + * TBAT look-up table is computed from the R90 reg (8 bit register)
> + * as below.
> + * TBAT = 1/(t1+1/298) - 273
> + * where t1 = (1/B)* ln(( ADCval * 2.5)/(R25*ITBAT*255))
> + * Default values are R25 = 10e3, B = 3380, ITBAT = 50e-6
> + * Example:
> + * R25=10E3, B=3380, ITBAT=50e-6, ADCVAL=62d calculates
> + * TBAT = 20 degrees Centrigrade
> + * For R90 reading of 0, a value of -1 is returned, as log of 0
> + * is undefined.
> +*/
> +static const int8_t tbat_lookup[] = {
Array should have a fixed size, to avoid size mismatches.
> + -1, 183, 144, 124, 111, 102, 94, 88, 83, 79, 75, 72, 69, 66, 63,
-1 here doesn't provide any useful value here. Presumably it means an
error, but it does not really reflect one, but results in a temperature
of -1 degrees C. If an index value of 0 reflects an error, you should
check that value before the lookup and return an error instead of a
temperature of -1 degress C. Also see below.
> + 61, 59, 57, 55, 53, 52, 50, 49, 48, 46, 45, 44, 43, 42,
> + 41, 40, 39, 38, 37, 36, 35, 35, 34, 33, 32, 32, 31, 30,
> + 30, 29, 28, 28, 27, 27, 26, 26, 25, 25, 24, 24, 23, 23,
> + 22, 22, 21, 21, 20, 20, 20, 19, 19, 18, 18, 18, 17, 17,
> + 17, 16, 16, 16, 15, 15, 15, 14, 14, 14, 13, 13, 13, 12,
> + 12, 12, 12, 11, 11, 11, 11, 10, 10, 10, 10, 9, 9, 9,
> + 9, 8, 8, 8, 8, 7, 7, 7, 7, 7, 6, 6, 6, 6,
> + 6, 5, 5, 5, 5, 5, 4, 4, 4, 4, 4, 3, 3, 3,
> + 3, 3, 3, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1,
> + 1, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1, -1, -1, -1,
> + -2, -2, -2, -2, -2, -2, -2, -3, -3, -3, -3, -3, -3, -3,
> + -3, -4, -4, -4, -4, -4, -4, -4, -4, -5, -5, -5, -5, -5,
> + -5, -5, -5, -5, -6, -6, -6, -6, -6, -6, -6, -6, -6, -7,
> + -7, -7, -7, -7, -7, -7, -7, -7, -8, -8, -8, -8, -8, -8,
> + -8, -8, -8, -8, -8, -9, -9, -9, -9, -9, -9, -9, -9, -9,
> + -9, -10, -10, -10, -10, -10, -10, -10, -10, -10, -10, -10, -10, -11,
> + -11, -11, -11, -11, -11, -11, -11, -11, -11, -11, -12, -12, -12, -12,
> + -12, -12, -12
> +};
> +
> +static int da9052_enable_vddout_channel(struct da9052 *da9052)
> +{
> + int ret;
> +
> + ret = da9052_reg_read(da9052, DA9052_ADC_CONT_REG);
> + if (ret < 0)
> + return ret;
> +
> + ret |= DA9052_ADCCONT_AUTOVDDEN;
> + return da9052_reg_write(da9052, DA9052_ADC_CONT_REG, ret);
> +}
> +
> +static int da9052_disable_vddout_channel(struct da9052 *da9052)
> +{
> + int ret;
> +
> + ret = da9052_reg_read(da9052, DA9052_ADC_CONT_REG);
> + if (ret < 0)
> + return ret;
> +
> + ret &= ~DA9052_ADCCONT_AUTOVDDEN;
> + return da9052_reg_write(da9052, DA9052_ADC_CONT_REG, ret);
> +
> +}
> +
> +static ssize_t da9052_read_vddout(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int ret, vdd = -1;
> +
> + mutex_lock(&hwmon->hwmon_lock);
> +
> + ret = da9052_enable_vddout_channel(hwmon->da9052);
> + if (ret < 0)
> + goto hwmon_err;
> +
> + ret = da9052_reg_read(hwmon->da9052, DA9052_VDD_RES_REG);
> + if (ret < 0)
> + pr_err("failed to read VDD_RES_REG\n");
> + else
> + vdd = ret;
> +
> + ret = da9052_disable_vddout_channel(hwmon->da9052);
> + if (ret < 0)
> + goto hwmon_err;
> +
> + if (vdd >= 0) {
> + mutex_unlock(&hwmon->hwmon_lock);
> + return sprintf(buf, "%d\n", vdd);
> + }
> +hwmon_err:
> + mutex_unlock(&hwmon->hwmon_lock);
> + return ret;
> +}
> +
> +static ssize_t da9052_read_ich(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = da9052_reg_read(hwmon->da9052, DA9052_ICHG_AV_REG);
> + if (ret < 0)
> + return ret;
> +
> + /* Equivalent to 3.9mA/bit in register ICHG_AV */
> + ret = DIV_ROUND_CLOSEST(ret * 39, 10);
> + return sprintf(buf, "%d\n", ret);
return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret * 39, 10));
> +}
> +
> +static ssize_t da9052_read_tbat(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int ret, tbat;
> +
> + ret = da9052_reg_read(hwmon->da9052, DA9052_TBAT_RES_REG);
> + if (ret < 0)
> + return ret;
> +
> + tbat = tbat_lookup[ret];
What if ret >= 256 ? I think you should have something like
if (ret == 0 || ret >= ARRAY_SIZE(tbat_lookup))
return -EIO;
> + return sprintf(buf, "%d\n", (tbat*1000));
You are unnecessarily loosing accuracy here. You might consider using a
16-bit table and store temperatures in 10-th of degree C. Also, with
return sprintf(buf, "%d\n", tbat_lookup[ret] * 1000);
you would no longer need tbat.
> +}
> +
> +static ssize_t da9052_read_vbat(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = da9052_adc_manual_read(hwmon->da9052, DA9052_ADC_VBAT);
> + if (ret < 0)
> + return ret;
> +
> + return sprintf(buf, "%d\n", ret);
> +}
> +
> +static ssize_t da9052_read_misc_channel(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int channel = to_sensor_dev_attr(devattr)->index;
> + int ret;
> +
> + ret = da9052_adc_manual_read(hwmon->da9052, channel);
> + if (ret < 0)
> + return ret;
> +
> + return sprintf(buf, "%d\n", ret);
> +}
> +
> +static ssize_t da9052_read_tjunc(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int temp;
> + int ret;
> +
> + ret = da9052_reg_read(hwmon->da9052, DA9052_TJUNC_RES_REG);
> + if (ret < 0)
> + return ret;
> +
> + temp = ret;
Instead of reading ret and assigning to temp, you can assign to temp
directly. Saves you the additional assignment. And if you were to use
variable names such as tjunc and toffset instead of temp and ret, the
variable names would actually have some meaning.
> +
> + ret = da9052_reg_read(hwmon->da9052, DA9052_T_OFFSET_REG);
> + if (ret < 0)
> + return ret;
> +
> + /* Degrees celsius = 1.708 * (TJUNC_RES - T_OFFSET) - 108.8 */
> + ret = 1708 * (temp - ret) - 108800;
> + return sprintf(buf, "%d\n", ret);
You can do that calculation directly. No need to assign to ret.
return sprintf(buf, "%d\n", 1708 * (temp - ret) - 108800);
> +}
> +
> +static ssize_t da9052_read_vbbat(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = da9052_adc_manual_read(hwmon->da9052, DA9052_ADC_VBBAT);
> + if (ret < 0)
> + return ret;
> +
> + return sprintf(buf, "%d\n", ret);
> +
> +}
> +
> +static ssize_t da9052_hwmon_show_name(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + return sprintf(buf, "da9052-hwmon\n");
> +}
> +
> +static ssize_t show_label(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + return sprintf(buf, "%s\n",
> + input_names[to_sensor_dev_attr(devattr)->index]);
> +}
> +
> +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, da9052_read_vddout, NULL,
> + DA9052_ADC_ICH);
> +static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_ICH);
> +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, da9052_read_vbat, NULL,
> + DA9052_ADC_VBAT);
> +static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_VBAT);
> +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, da9052_read_misc_channel, NULL,
> + DA9052_ADC_IN4);
> +static SENSOR_DEVICE_ATTR(in4_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_IN4);
> +static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, da9052_read_misc_channel, NULL,
> + DA9052_ADC_IN5);
> +static SENSOR_DEVICE_ATTR(in5_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_IN5);
> +static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, da9052_read_misc_channel, NULL,
> + DA9052_ADC_IN6);
> +static SENSOR_DEVICE_ATTR(in6_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_IN6);
> +static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, da9052_read_vbbat, NULL,
> + DA9052_ADC_VBBAT);
> +static SENSOR_DEVICE_ATTR(in9_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_VBBAT);
> +static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, da9052_read_ich, NULL,
> + DA9052_ADC_ICH);
> +static SENSOR_DEVICE_ATTR(curr1_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_ICH);
> +
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, da9052_read_tbat, NULL,
> + DA9052_ADC_TBAT);
> +static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_TBAT);
> +
> +static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, da9052_read_tjunc, NULL,
> + DA9052_ADC_TJUNC);
> +static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
> + DA9052_ADC_TJUNC);
> +
> +static DEVICE_ATTR(name, S_IRUGO, da9052_hwmon_show_name, NULL);
> +
> +static struct attribute *da9052_attr[] = {
> + &dev_attr_name.attr,
> +
> + &sensor_dev_attr_in0_input.dev_attr.attr,
> + &sensor_dev_attr_in0_label.dev_attr.attr,
> + &sensor_dev_attr_in3_input.dev_attr.attr,
> + &sensor_dev_attr_in3_label.dev_attr.attr,
> + &sensor_dev_attr_in4_input.dev_attr.attr,
> + &sensor_dev_attr_in4_label.dev_attr.attr,
> + &sensor_dev_attr_in5_input.dev_attr.attr,
> + &sensor_dev_attr_in5_label.dev_attr.attr,
> + &sensor_dev_attr_in6_input.dev_attr.attr,
> + &sensor_dev_attr_in6_label.dev_attr.attr,
> + &sensor_dev_attr_in9_input.dev_attr.attr,
> + &sensor_dev_attr_in9_label.dev_attr.attr,
> + &sensor_dev_attr_curr1_input.dev_attr.attr,
> + &sensor_dev_attr_curr1_label.dev_attr.attr,
> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> + &sensor_dev_attr_temp1_label.dev_attr.attr,
> + &sensor_dev_attr_temp2_input.dev_attr.attr,
> + &sensor_dev_attr_temp2_label.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group da9052_attr_group = {.attrs = da9052_attr};
> +
> +static int __init da9052_hwmon_probe(struct platform_device *pdev)
> +{
> + struct da9052_hwmon *hwmon;
> + int ret;
> +
> + hwmon = kzalloc(sizeof(struct da9052_hwmon), GFP_KERNEL);
> + if (!hwmon)
> + return -ENOMEM;
> +
> + mutex_init(&hwmon->hwmon_lock);
> + hwmon->da9052 = dev_get_drvdata(pdev->dev.parent);
> +
> + platform_set_drvdata(pdev, hwmon);
> +
> + ret = sysfs_create_group(&pdev->dev.kobj, &da9052_attr_group);
> + if (ret)
> + goto err_mem;
> +
> + hwmon->class_device = hwmon_device_register(&pdev->dev);
> + if (IS_ERR(hwmon->class_device)) {
> + ret = PTR_ERR(hwmon->class_device);
> + sysfs_remove_group(&pdev->dev.kobj, &da9052_attr_group);
> + goto err_mem;
Please use the commonly used error path cleanup.
ret = PTR_ERR(hwmon->class_device);
goto err_sysfs;
> + }
> +
> + return 0;
> +
err_sysfs:
sysfs_remove_group(&pdev->dev.kobj, &da9052_attr_group);
> +err_mem:
> + kfree(hwmon);
> + return ret;
> +}
> +
> +static int __devexit da9052_hwmon_remove(struct platform_device *pdev)
> +{
> + struct da9052_hwmon *hwmon = platform_get_drvdata(pdev);
> +
> + hwmon_device_unregister(hwmon->class_device);
> + sysfs_remove_group(&pdev->dev.kobj, &da9052_attr_group);
> + kfree(hwmon);
> + return 0;
> +}
> +
> +static struct platform_driver da9052_hwmon_driver = {
> + .driver = {
> + .name = "da9052-hwmon",
> + .owner = THIS_MODULE,
> + },
> + .probe = da9052_hwmon_probe,
> + .remove = __devexit_p(da9052_hwmon_remove),
> +
> +};
> +
> +static int __init da9052_hwmon_init(void)
> +{
> +
> + return platform_driver_register(&da9052_hwmon_driver);
> +}
> +module_init(da9052_hwmon_init);
> +
> +static void __exit da9052_hwmon_exit(void)
> +{
> + platform_driver_unregister(&da9052_hwmon_driver);
> +}
> +module_exit(da9052_hwmon_exit);
> +
> +MODULE_AUTHOR("David Dajun Chen <dchen@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("DA9052 HWMON driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:da9052-hwmon");
> +
> +
Empty lines at the end will cause a git warning,
>
>
> Regards,
> Ashish
>
... and there should be no additional text after the end of the patch.
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